More particularly, the invention relates to a hydraulic antivibration sleeve comprising two tubular rigid strength members one surrounding the other, namely an inner strength member and an outer strength member having respective longitudinal axes parallel to a common axial direction and interconnected by an elastomer body, the antivibration sleeve including at least two sealed pockets fully defined by the elastomer body and the two strength members, said sealed pockets being disposed between the two strength members and communicating with each other via at least one narrow channel, the two pockets and the narrow channel together being filled with a liquid, the elastomer body extending axially between first and second ends, the elastomer body including an inner annular portion molded on and bonded to the inner strength member and an outer annular portion in contact with the outer strength member, and the elastomer body further including at least two solid portions angularly separating the pockets from one another.
An example of such a hydraulic antivibration sleeve is given in document EP-A-0 359 655.
Hydraulic antivibration sleeves of the kind in question suffer from the drawback of requiring complex molds having two radially-moving shells and two portions that move axially. This gives rise firstly to high cost molding and secondly to productivity which is limited by the small number of mold cavities that can be provided in the same mold.
Also, hydraulic antivibration sleeves of the kind in question include a perforated metal cage on which the outer annular portion of the elastomer body is molded and bonded, the outer tubular strength member being fitted around the perforated cage after the elastomer body has been molded.
The perforated cage is a metal part of relatively complex shape and is therefore expensive, and it also increases the weight of the hydraulic antivibration sleeve.